哈希加盐法加密用户密码代码实现

这是从Microsoft.AspNet.Identity 中提取出来的。

    class Crypto
    {
        private const int PBKDF2IterCount = 1000;
        private const int PBKDF2SubkeyLength = 32;
        private const int SaltSize = 16;

        public static string HashPassword(string password)
        {
            if (password == null)
            {
                throw new ArgumentNullException("password");
            }
            byte[] salt;
            byte[] bytes;
            using (Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(password, 16, 1000))
            {
                salt = rfc2898DeriveBytes.Salt;
                bytes = rfc2898DeriveBytes.GetBytes(32);
            }
            byte[] array = new byte[49];
            Buffer.BlockCopy(salt, 0, array, 1, 16);
            Buffer.BlockCopy(bytes, 0, array, 17, 32);
            return Convert.ToBase64String(array);
        }

        public static bool VerifyHashedPassword(string hashedPassword, string password)
        {
            if (hashedPassword == null)
            {
                return false;
            }
            if (password == null)
            {
                throw new ArgumentNullException("password");
            }
            byte[] array = Convert.FromBase64String(hashedPassword);
            if (array.Length != 49 || array[0] != 0)
            {
                return false;
            }
            byte[] array2 = new byte[16];
            Buffer.BlockCopy(array, 1, array2, 0, 16);
            byte[] array3 = new byte[32];
            Buffer.BlockCopy(array, 17, array3, 0, 32);
            byte[] bytes;
            using (Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(password, array2, 1000))
            {
                bytes = rfc2898DeriveBytes.GetBytes(32);
            }
            return ByteArraysEqual(array3, bytes);
        }

        [MethodImpl(MethodImplOptions.NoOptimization)]
        private static bool ByteArraysEqual(byte[] a, byte[] b)
        {
            if (object.ReferenceEquals(a, b))
            {
                return true;
            }
            if (a == null || b == null || a.Length != b.Length)
            {
                return false;
            }
            bool flag = true;
            for (int i = 0; i < a.Length; i++)
            {
                flag &= (a[i] == b[i]);
            }
            return flag;
        }
    }